Question / Help Downscale VS Rescale

[jugganuts]

Hello everyone! First post

So i guess this is more of a technical question with obs studio.

so i notice there are two ways to change your resolution in the settings one in the video settings which is downscale and one is in the encoding settings which is rescale

so i guess my questions are how are each of these implemented eg. cpu load vs gpu load and and best quality vs performance

like which is more efficient

which one looks better

which chips do they utilize

what would be considered redundant

oh and fyi im using nvec x264 as my encoder

thanks for the help i know there is another post out there which vaguely talks about it but i was hoping for more details!

THANKS AGAIN!

 

[RytoEX]

Scaling your output in Video settings makes your GPU rescale your video frames before being sent to the encoder. Rescaling the output in the Output (Encoder) settings makes your encoder perform the scaling. The encoder can be x264 on the CPU, NVENC (on qualifying nVidia GPUs), or H264/AVC Encoder (for qualifying AMD GPUs). In nearly all cases, scaling on the GPU should be more efficient. The only time this might not be true is if you have a very old or low-spec GPU and a very new or high-spec CPU, but I'm not sure about that.

I don't know about which scaling looks better. I would guess the Video/GPU scaling using Lanczos would look better in most cases, but again, I may be wrong, and your mileage may vary.

 

[Sapiens]

Generally you want to use the downscale option under Settings > Video for the reasons RytoEX mentioned (more efficient and the availability of filtering). The rescale option under Settings > Output is primarily used when you want to stream and record at different resolutions.

 

[jugganuts]

Thanks for the great replys people i did some testing and found that re-scaling in output looked better to my eyes "lil blurrier" vs down-scaling which looked a lil more "blocky" but too much load on 1 core of the cpu (around 40% constant). So down-scaling it is!

hope this post helps others!